1. Field of the Invention
The present invention is directed to wellbore operations, top drives, top drive casing systems and operations, torque heads, top drives with torque heads, and methods using them.
2. Description of Related Art
The prior art discloses many systems and methods for running casing. The prior art also discloses a variety of systems using a top drive for running casing. Certain prior art top drive systems include the attachment of a spider (e.g. but not limited to, a flush mounted spider) suspended beneath a top drive from the bails. The bails are then rigidly fastened to a top drive quill so as to cause the flush mounted spider to rotate in unison with any rotation of the quill. Engagement of the flush mounted spider""s slips with a casing joint or string causes the casing to rotate in coordinated unison with the spider. FIG. 17 shows a prior art top drive in which the collective assembly beneath a bull gear is able to rotate and is collectively referred to as the xe2x80x9cpipe handlingxe2x80x9d or xe2x80x9chandlerxe2x80x9d system. This pipe handling system can be made to slue in coordination with the quill by rigidly affixing the bails to the quill. In certain embodiments of such a system since the top drive""s pipe handling system rotates with the tool at all times, rotation is limited to the design speed limit of the system""s seals and bearingsxe2x80x94about 6 rpm in some cases. This can add many hours to a casing job. The present inventors have recognized that a system is needed that can rotate significantly faster during the spin-in phase of makeup, like a tong and which would only engage a pipe handler to turn the tool after makeup if there is a stuck pipe situation. Another disadvantage with such systems is that by making the torque head the primary hoisting device the cost of the device is increased and also, in many cases, makes it necessary to produce or own different size/tonnage range torque head assemblies to cover both different size rangesxe2x80x94and within size ranges, different tonnages. The present inventors have recognized a need for a system that allows a rig to utilize hoisting equipment it already owns for primary hoisting and a system with a torque head that is lighter, i.e. a less expensive device capable of use universally within a size range regardless of tonnage requirements.
With many known prior art devices, apparatuses and systems with which casing is gripped, e.g. by jaws, inserts, or dies, the casing is damaged. Such damage can result in casing which cannot be used. When premium tubulars are required, such damage is very expensive.
There has long been a need for an efficient and effective system and method for running casing (making-up and breaking-out connections) with a top drive. There has long been a need for such a system and method which provides for continuous fluid circulation during running operations. There has long been a need for such a system and method that efficiently and effectively rotates casing and applies downward force on a casing string while the string is being installed in a wellbore. There has long been a need for such systems and methods which reduce damage to casing. There has long been a need for such a system and method wherein an apparatus that grips casing does not become locked on the casing.
The present invention, in certain aspects, provides a system with a top drive and its related apparatus, and a torque head connected to and below the top drive in a rig for selectively gripping casing. The present invention, in certain embodiments, discloses a torque head useful in such systems and methods, the torque head with jaws with grip members, including but not limited to, slips, dies, and inserts; and in one particular aspect slips with movable dies or inserts that have some degree of axial freedom with respect to the jaws so that, in one aspect, when the slips first contact the exterior of a casing section the dies or inserts move axially with respect to the casing rather than radially, i.e. initially they do not bite, or bite only minimally, into the casing. Then, as the casing is moved by the top drive slips allow limited vertical movement both upward and downward. This allows the slips, dies or inserts to move upward relative to the slips as they engage the casing and to move downward relative to the slips as they are disengaged from the casing.
In certain embodiments a fluid circulation tool or apparatus is mounted in a torque head according to the present invention. Part of this tool is introduced into the top of a casing joint when the joint is being hoisted and readied for makeup to a casing string. With appropriate sealing packers, the joint is filled with circulation fluid and then moved into position above the casing string. Once makeup commences, circulating fluid is circulated through the joint and to the casing string.
In certain particular embodiments of the present invention relative axial movement of the torque head with respect to a casing joint being gripped by the slips is also made possible by providing a mounting plate assembly that includes bolts holding it together and springs that allow some controlled axial movement of the torque head. With the slips gripping the casing, a torque head barrel is rigidly fixed relative to the casing and if the casing is made up to the string or is gripped at the spider, downward force on the torque head assembly causes the springs located in the top plate to compress and allows for limited axial movement relative to the casing and elevator, provided the elevator slips are engaged on the casing. Such a torque head can be used with the previously-mentioned movable dies, etc., (which engage the casing when they are moved axially downwardly relative to the inner diameter of the torque head) and which are disengaged by axial movement upwardly relative to an inner diameter of the torque head. In the event the torque head assembly is subjected to a dangerous axial load of predetermined amount (e.g., but not limited to, about 100 tons or more), the bolts fail before significant damage is done to the torque head. When the bolts fail, the top plate assembly separates from the torque head barrel while the slips of the torque head assembly remain engaged against the casing, thus causing the barrel and slip mechanism within the barrel to remain firmly attached to the casing and prevent it from free falling the rig floor. This also reduces the possibility of items falling down (e.g. the torque head) and injuring personnel.
In certain aspects, selectively controlled piston/cylinder devices are used to move the slips into and out of engagement with a casing joint. In certain embodiments the piston/cylinder assemblies have internal flow control valves and accumulators so that once the slips engage the casing, hydraulic pressure is maintained in the cylinders and the slips remain in engagement with the casing.
Methods according to the present invention with systems according to the present invention are more automated than previous systems because in various prior art systems the torque head can become locked onto the casing when the slips of an elevator (or other suspension/clamping device) are engaged against the casing after the slips of the torque head have been engaged. This condition is a result of the actuation of hydraulic cylinders and then not being able to provide sufficient force to disengage the slips and overcome the mechanical advantage created by the wedging action of slip assemblies without some relative vertical movement of the casing. With the slips of the elevator set, this relative vertical movement of the casing is prevented. The same condition exists for the slips of the elevator in various prior art systems so that the torque head and elevator are locked onto the casing. Various methods are employed to prevent or preclude the torque head from becoming locked onto the casing. In one aspect the dies are capable of some vertical movement relative to the slips. In another aspect in the torque head barrel some limited vertical movement relative to the casing is allowed due to the two piece construction of the torque head barrel top assembly with incorporated spring washers. When the need to use a power tong to makeup a casing string is eliminated, as with systems according to the present invention, the need for a tong running crew is also eliminated.
It is, therefore, an object of at least certain preferred embodiments of the present invention to provide: New, useful, unique, efficient, and novel and nonobvious system and methods for running casing with a top drive;
Such systems and methods which provide automated operations;
Such systems and methods which provide continuous fluid circulation during operations;
Such systems and methods which reduce or eliminate damage to casing by using grippers with movable dies or inserts (marking or non-marking); that prevent a torquing apparatus from becoming locked onto casing and/or which reduce or eliminate axial loading on a torquing apparatus and/or by providing for shear release of the torque head from an item, e.g. a top drive connected to it
Certain embodiments of this invention are not limited to any particular individual feature disclosed here, but include combinations of them distinguished from the prior art in their structures and functions. Features of the invention have been broadly described so that the detailed descriptions that follow may be better understood, and in order that the contributions of this invention to the arts may be better appreciated. There are, of course, additional aspects of the invention described below and which may be included in the subject matter of the claims to this invention. Those skilled in the art who have the benefit of this invention, its teachings, and suggestions will appreciate that the conceptions of this disclosure may be used as a creative basis for designing other structures, methods and systems for carrying out and practicing the present invention. The claims of this invention are to be read to include any legally equivalent devices or methods which do not depart from the spirit and scope of the present invention.
The present invention recognizes and addresses the previously-mentioned problems and long-felt needs and provides a solution to those problems and a satisfactory meeting of those needs in its various possible embodiments and equivalents thereof. To one skilled in this art who has the benefits of this invention""s realizations, teachings, disclosures, and suggestions, other purposes and advantages will be appreciated from the following description of preferred embodiments, given for the purpose of disclosure, when taken in conjunction with the accompanying drawings. The detail in these descriptions is not intended to thwart this patent""s object to claim this invention no matter how others may later disguise it by variations in form or additions of further improvements.